Can't walk in high heels, but still a slave to fashion? A new formula devised by British physicists may be able to help you determine how high a heel you can safely handle -- before and after a few cocktails.

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"Although at first glance our formula looks scary," says formula creator Paul Stevenson of the University of Surrey, in a news release, "it's actually pretty simple as it's based on the science you learnt at school and which you never thought you would use in real life." By applying this formula, a person can determine just how high the heel of the foot can be lifted above the ground with out falling over.

The 'Q' factor
But the hard part was working out the elusive "Q" factor. That's the sociological part of the equation not based on the mere mechanics of the shoes.

"Essentially this part of the formula explains what women have always known -- that you don't buy shoes just because they are comfortable, you can afford them, and they look good -- many other variables come into play," says Stevenson.

p: The probability that wearing the shoes will help you attract a mate, or "pull" in Brit-speak (in a range from 0 to 1, where 1 is a sure draw and 0 is no chance) y: The number of years of experience the wearer has in wearing high heels. More experienced wearers can handle a higher heel, but beginners should take it easy. L: The cost of the shoes, in British pounds. The more expensive, the more likely women will put up with a higher heel. t: The time since the shoe was the height of fashion, in months (0 = it's red hot right now). If the shoes are terribly fashionable, wearers should be prepared to put up with a little pain. A: Units of alcohol consumed. The more alcohol that's consumed, the more risky wearing high heels becomes, no matter how well the martini glass goes with the shoes.

Handicapping Carrie Bradshaw's heels
Using this formula, researchers estimate that if Sex and the City's Carrie Bradshaw, who is an experienced high-heel wearer with at least five years' experience, wears her latest gorgeous designer originals when sober, she can cope with a heel height of a staggering more than 5 inches (12.5 centimeters).

But if she has one too many cosmopolitans, the "safe" heel height drops dramatically. Using the same example as above, if she consumes 6 units of alcohol she would be advised to stick to heels with a height of less than one inch (2 cm).

Laura Grant, a physicist from Liverpool University, welcomes the institute's new formula.

"Many of my physicist colleagues have no trouble understanding quantum mechanics but can't figure out how women can wear high heels. Now I can explain to them how I minimize the probability of tripping up," says Grant.